Moist materials such as, for example, suspensions, sludges, filter cakes, pastes and moist solids as well as salts containing crystal water can occasionally be difficult to handle. In this regard, the poor storage and transport properties of moist materials are a particular problem. Particularly with finely divided materials, removing the moisture is often only accomplished with difficulty. Because of the moisture and occasional thixotropic behavior of such materials, caking or adhesion often occurs during transport, storage or processing.
Under high mechanical loads such as, for example during pulverizing/drying, moreover, problems with abrasion often arise. In addition, problems frequently arise linked to dust formation during drying.
Problems with handling moist materials which are recognized in the prior art are as follows:                insufficient reduction in the moisture content: mechanical dewatering results in moist materials which often have only a 20% to 50% by weight dry matter content,        the moist materials are not easy to handle, and in particular have an annoying tendency to cake and stick upon storage and transport, as well as a tendency towards thixotropy,        larger particles, for example fragments of a filter cake from a filter press, often exhibit a moisture gradient within the particle: the particle interior is still wet, while the exterior is dusty,        in conventional drying methods, removing dust from the streams of gas employed for drying is expensive,        often, transport or drying causes increased abrasion.        
The problems with handling pulverulent or dusty materials are generally known and are essentially unwanted dust formation in open systems and poor conveying and metering characteristics during transport.